The invention relates to a drive unit for electric rail vehicles according to the preamble of the patent claim. A drive unit of this type is disclosed in DE-OS 21 06 662.
Particularly for fast-moving vehicles, the masses of non-spring-suspended components are intended to be kept as small as possible, to greatly contribute to preserving the guideway and to influence the riding performance. Therefore, for high-speed vehicles, fully spring-suspended drives have been generally accepted. For this purpose, the traction motors together with the geared transmissions are usually mounted in bogie frames and the torque transmission between transmission and the non-spring-suspended wheel sets (shaft with wheels) is designed such that relative movements can be absorbed within the framework of the spring deflections.
In contrast, there is the simply designed, classic nose-suspended drive whose most pronounced drawback, however, is that there are considerable reactions of the high portion of non-spring-suspended mass forces because of the direct, rigid support on the wheel set shaft. These reactions impair the vehicle dynamics in such a way that nose-suspended drives are ill-suited for higher running speeds. In these drives, there is no mobility transversely to the direction of travel (y-mobility) of the wheel set shaft.
By means of the drive unit known from the DE-OS 21 06 662 mentioned at the outset, the fully spring-suspended drives are simplified along the lines of non-spring-suspended drives and the advantages of both types of drives are combined in an advantageous drive system which reduces the mass forces in drives similar to nose-suspended drives by means of transverse flexibility.
In this drive unit according to DE-OS 21 06 662, the hollow shaft, on which the greater wheel of the transmission is seated and which surrounds the shaft of the wheel set, is supported against the driving wheel via an articulated lever coupling. But such an articulated lever coupling requires a relatively large amount of space. While it allows an axial mobility via an excursion of the articulated levers, this mobility manifests itself in a disadvantageous manner in the form of resilient restoring forces. These restoring forces, in turn, lead to undesirable axial vibrations of the articulated levers and thus of the drive unit.
According to DE 34 38 088 C1, a rubber-elastic coupling is provided for the transmission of force between a hollow shaft surrounding the driving axle of an electric rail vehicle and a driving wheel, which coupling is arranged between two metal rings disposed between a disk which is seated on the hollow shaft and a coupling disk which is screwed to the driving wheel. Here, the driving wheel is recessed on both sides of the wheel disk in the manner of an annular disk.